In addressing the title of the post, I'll speculate that most of these trees are what I'd call garbage or weed trees: typically fast growing (and weak wood). In the pictures with cut grass, the vehicle serves as a decorative planter.
The wood is useless and even stinks like sulfur when cut... Not to mention the metric ton of "fuzz" that coats every surrounding AC condenser. In the pictures with cut grass, the vehicle serves as a decorative planter